And edwabd



Patented Feb. 19, 1929.

UNITED STATES PATENT OFFICE.

LINN BRADLEY, OF IVION'ICLAIR, NEWV' JERSEY, AND EDYVARD P. IVICKEEFE, OF NEW YORK, N. Y., ASSIGNOBS 'lO BRADLEY-MCKEEFE CORPORATION, OF NEW YORK, N. Y.,

A CORPORATION OF NEl/V YORK.

PRODUCTION OF CAUSTIC ALKALI AND OTHER PRODUCTS.

No Drawing. Application filed November 5, 1921, Serial No. 513,182. Renewed May 5, 1927.

This invention relates to the production of caustic alkalis. and more particularly to the production of caustic alkalis from alkali-uietal sullites and from products produced therefrom. The invention also includes improvements in the production oi furnace products containing alli'ali-iuetal carbides, and in the production of acetylene. as well as caustic allcili's, therefrom.

According to the present inventiiin a solution of alkali-metal sultite is dig, ed with a. cellulose-heari11g material. such as wood. until the interaction between the alhaliauetal white and the non-cellulose constituents of the wood results in the solution of the nontibrous material and produces a residual liquor containing the soluble products of interaction oi the alkali-metal suiiitc upon certain of the wood constituents. The residual liquor is then separated from the fibrous material, cmporatcd to dryness and the dried product is calcined and the calcined product, with added carlmnaccous material it required, heated to a sufiicient tcn'ipcrature to term a furnace product containing some alkali-metal car-hide. The furnace product containing carbide may be treated. for exanigi by subjecting it to the ction of steam in regulated amount and under properly regulated conditions whereby the steam will react. with the carbide to produce acetylene, or acetylene with other combustible gases, and caustic a l The iufl. by the Folio may be Further illustrated more detailed description, but it is intended d will be undcrstmnl that the inrcutii'in iii! strated by but is not iililitcd to ti. 3 spec: 1c bXtllllplOH so d scribed.

A soli..i n o't' nornui sodium suliite (M1 digested with chipped wood for example, poplar or spruce wood or other coniferous or deciduous wood. using about SOQb- LOA or the sodium sultite (Na SU based on the air-dried weight of he wood, and using a sutlicicnt amountof water so that the wood chips are covered by the sodium suliite solution. The digestion may he carried out by heating: with direct steam at a steam pressure varying from about 110 to 114:0 pounds. and the digestion can he continued for a suitable period of time. for example, from ten to three hours. or until the wood fibres are substantially freed from nonfibrous constituents. As a result of the digest-ion above described, the cellulosic material itself (i. e. the wood) is in part utilized in reiu'rtine; with or couibiniiug,- with some of the sodium sultite. white a part of the wood is converted into a high grade pulp which is thus produced as one of the i 'aluable products of the cou'uih ;c process.

The residual liquors produced by the dige tion above described will contain large amounts of organic compounds, a greater or lesr; r-ortion of which will he sodiuiirorganic compounds or oodiuiii-sililo-organic compounds. The liquor may also contain unchanged sodium sullite as well as other products. 'l'hcse liquors have a characteristic coimositiou a d they seem to contain considerable amounts oi organic acids or readily oxidizabie compounds.which, on oxidatioii, yield organic acids. These organic acids or :u-id-iormiug: ((HillJOlllltlS. when the liquor is concentrated and cvapora ted to dryness. seem to react upon me sodium sullitc oi the solution and other sultur-containing couuioiuuls so that the greater part of the sulfur dioxide oi the sodium sultite employed is set free and driven oil". Also some carbon disultide may be formed and thus remove some sulfur compounds in this way.

The evaporation of the solution may ho carried out. in diliercnt ways. The solution may. tor evamplc. he cv=u oratcd in a multiple eiiect evaporator until it has a spcciiic gz ravitv of about lo -(so 'lw. and the coin-ea irate-d liquor iidil fed into a rotary 'l'urnace such as is commonly used in the calciual ion of concentrated lil:l('l{ liquor produced by the soda polo prove The rotary furnace may be heated. i'or example, by nieaus of a coal lire at the lower end, that is. at the discharge end, and the hot gases from the furnace may be utilized for heating or the generation of steam in a boiler.

The dry product resulting from the evaporation, and preferably after it has been preliminarily calcined to drive off volatile organic matter such as results from destructivc distillation. together with added carbonaceous material if desired, heated in an electric furnace to a sullicient tei'nperature to convert a part at least of the sodium contained in the mixture into sodium carbide. The furnace may be similar to that used in the manufacture of calcium carbide. The heating of the electric furnace can be regu- 2 moo,

luted and controlled and u greater or less portion of the sodium content of the charge converted into sodiuin carbide.

The furnace product sodium or; rbid produced requires careful heuli' udrzmtugeous method of uti Hill-1 nuce product containing sodium cu ter it has been cooled, to subiect it LO tlu action of :1 regulated current of s will r act therewith to form onus a. valuable illuminetin The steam used in tre b *ontuining sodium curb .ic admixed With hi!" or carbon dioxi,

might react eiYier with the acetylene to un explcsi re mixture, or with the czzustie to tor-1n sodium 'urluinufe. l" regulating the action of the st upon the :turnure product containing st lldill carbide, danger of explosion can be u roided inininiized, While the caustic soda. 111: be pro duced in a concentrated state. ii

i properly acts upon the furnace prothict conta n 7 sodium carbide at a temperature such the; condensation of Water does not titlf i caustic soda may be produced in u. t "3 v The caustic soda. can be extracted from accompanying insoluble constituents; thus be obtained in the "form of z cone tinted solution if desired. The coinbu produced can be recovered and ut for heating or illuminating pu poses.

It will thus be seen that the present invei tion involves the production oi? sodium curbide and caustic soda from sodium suliite by at process in which the sodium suh te is subjected to the action of a. cellulose-be n 1118: teriel such as Wood, With the pror tion of pulp as one product and a residue iruior u the other, which residual liquor inn then be in he evaporated, calcined and heater. in an dertric furnace for the production of iii-nice product containing sodium carbide, 'Y. in turn, is treated with steam tor th o From (1 HUGE.

' i i c H l a, V i be cousiuei to the.

duration oil can ilpoint, it n 1011 involves the treutine bearing inuteriul din esti 1 of alkali-metal suifite toe coolqii and in which the residual liquor is t the manner above described.

Instead of using: sodium sulli'te in the roc hr in h ",1 A. .e. ehicn (on duction of carbide.

method of producii cu sch-metal suliites W r a solution or the u u cellulose-been h ll " and heating r l e a furnace p1 odu tel carbide therefrom,

furnace product with nu" '1 of caustic St "a i? liSQES eru 30111 the (l uncunt st r all lliuli-nietul curhide. u process for hydroxide, the steps WillCll include wood with cooking liq stumble con'iposition uni properties eluding e suh-nuntiul :nnoun t of u sulli Llll-1Del'2f, under conditions ud Jlti u rosi rul' iuetul a ul liquor-Which no Mon and 'Jucinei rtion in :1 it rotary type such us is ei'iplo red up bloc-q liquors (1 th ouven is cupube uses 5n i i coinbi i r uor when chur g erl into the d separating residrul liquor troin refibrous inateriu removing Water from residual liquor and Furnztcingr the residue under conditions adapted to form furwhich carry the greater amount nice " the sul'lur present in the cooling liquor o -i- {1S sulfite ot' on alkali-metal and under eon dni adapted to yielc tun see product includiig ullmli-n'ietnl compounds of which z preponderuting; amount is chil -metal urbonute, and treating such iturnuce product to produce an elkuliunetul hydre b ide.

6. in u process for producing ullreliinetul hydroxide, the steps which include ii gcsting rood with a cooking liquor, of suitable composition and prope ties and including sulfur-bearing compounds of which at least one halt of the sult'ur is present as a sullite of an alkali-metal, under conditions adapted to yield a residual liquor which upon evaporation and incineration in a furnace of the rotary type such us is employed in working up black liquors of the conrentionz'rl soda process, is capable of yielding to the furnace gases the greater amount of the sulfur combined with alkali-metal in the cool:- ing liquor when charged into the dig estcr, separating; residual liquor from result c; fibrous materiel, removing water from residual liquor and furnacin y the residue under conditions adapted to form :lurnace gas s which carry the neuter umountol the irul'lur present in the cooking liquor as a sullite of an alkali-metal and under conditions adapted to yield a furnace product including alkali metal compoimds oi which a preponderatingr amount is an alkali-nu-lul carbonate, and treating such furnace product to prod uce an alkali-metal hydroxide.

7. In a process for producing an alkalimetal hydroxide, the steps which include di-- ce lulose-bearing material with an alkali'met-al inonosulfite-containiin; cooking; liquor, under conditions adapted to yield a residual liquor which upon c "operation and incineration in a furnace of the rotary type such as is employee in working up block liquors oi the conventional soda process, is capable of yielding to the furnuce gases the greater amount of the sulfur of the alkalimetal sullite in the cooking liquor when charged into the digestcr, separating residual liquor from resulting fibrous material, removing ater from residual liquor and furna the residue 1111(91 conditions adapted to form furnace gases which carry the nrcuter amount of the sulfur present in such cooking liquor as a sullito oi an alkulieuetul and under conditions :ulaptcd to yield a furnace product including alkali-metal compounds of which a preponde sting amount is an, alkali-metal urbonal'c, and treetin;- such furnace product to produce an alkali-metal hydroxide.

8. in a process for producing sodium hydroxide, the steps which include digesting wood by means oi a cooking liquor contain ing about to of sodium monosulfite (Na sO based on the air-dried weight of the wood, when charged into the digester and continuing the digesting treatment until the wood fibres are substantially freed from non-fibrous organic constituents or the wood, separating resulting residual liquor from resulting fibrous material, removing water from such residual liquor and furnacing the residue under conditions adapted to yield a furnace product containing a sulfur-free sodium compound and treating such furnace product to produce sodium hydroxide.

9. in a process for producing sodium hydroxide, the steps which include digesting wood by means oi a cooking liquor containing about Ill ,6 to ell. )6 of sodium inonosullite (iiafilld based on the air-dried weight oi the wood, when charged into the digcster and continuing the digesting treatment until the wood fibres are substantially freed from nondiln'ous organic constituents of the wood, separating resulting residual liquor :lrom resulting librour-i material, removing water tliroru such residual liquor and furnacing the residue under coiulitions adapted to yield a furnace product containing a sulturifreo sodiu in couqiound and treating such fornncc product to produce sodium hydroxide, such treatment including the steps ol il ornn inn; sodiiuu carbide and decomposing the sodi uui carbide to form sodium hydroxide.

ll). in a process for produciu; sodium or u cooking); liquor containt to l-llflt oit sodium mouosulby r1 inn; about li'lc (rlzuitith) busted n the air-dried weight oi the wood, -u charged into the dig'csl'er. d ((Jiiildlllllj-f lhc (llQ'OStlllfI treatment until irous or uu'zic constituents of the wood,

ring: resulting rcsiduul liquor from relibrous nuu'crial, removing; water from such residual liquor and 'lurnacing the residue under coi'ulitious adapted to yield a lur uco product containing: a sulfur-free sodium compound, at least a part of the furnaciiur treatment being carried out under conditions in which a current of hot gases is lmuurht im'o intimate contact with the material undergoing treatment, and treating such 'llll'lliill product to produce sodium hydrox dc.

1 n process for llllllllltlill' sodium hydrot;ide, llio steps which include digesting wood with a cooking liquor containing; about 30% to 40ft} oi sodium monosullite(P521 30 briscd on the air-dried weight of the wood until the wood librcs are substantially freed from non-fibrous consl dueuts, sepa atinp; resuiting r sidual liquor from resulting fibrous material, removing water from such residual liquor and furnacing the residue under conditious adapted to form furnace guses which carry the dfivzllll' amount of the sulfur present in such cooking liquor us sodium monosulfite when charged into the diiijostcr and under conditions adapted to yield a furnace product including sodium compounds, and tre i'ing sucu furnace product to produce sodium hydroxide.

. In a procfor Pr'OllllClilg sodium hydroxide, the steps which include digesting wood with a cooking liquor containing about 30% to 1-0)? of sodium monosulfite (Na SO based on the air dried weight of the Wood snlti'ng limaidnul liquor from 1365111" 111; mm, renmving water from liquor and tfm'nacing; the residue Jilin-m :15 VQQ to 01111 furnace g; warm t w greater 21 110111111 0f aha :Puch emulating when 0112" (1 into it: 2 di; Candi ions adamizd field a n1p 11nu$ inchlflinp' can'led (mi;

dnzf. tion and incineratiol'l in a in" wry type 5 16h as 1;; up black ilquors 0i nmww is cnnzabie 1mm) gaacs the V ,1 11 ongmzmy m 1 residml 1i )1 and v.crrnslc' the resid'uc- 1 C731 conditions adapted to form furalkali-111M111 11211-0 product hydroxide, such the 1'1, 11am mwtul of the urbirie (-zmsiirc Sod-.1,

to DI'OGUCQ dium hycarried Quimch as is -1 in wrking up black mg-3 3 ing the :fmnaci. 92w such 29211109 promlct 2E0 -;dioxide, such trc ment the furnace vraduct to JidG therefrom um product conaining for the production and rough 

